I thought EMI was Electromagnetic interference, which comes from all electronic devices. It was my iPod Classic. Tested it as well with my iPod Video. Same thing happened. I was testing the latest components that start shipping this month from JDS Labs. Apparently they changed a few things inside. Anyways, I couldn't find the time to do the review so I sent it back, unfortunately.

EDIT: Please keep in mind I'm using some pretty sensitive CIEM's....

Quote:

Originally Posted by ClieOS

EMI from iPod? I don't realize iPod is capable of radio wave emission (of significant level) at all. Are you sure it isn't the noise from some other components? For example, microdrive from older iPod, etc. I could understand if it is an iPhone cause those are known to be real bad with EMI (I am using a Samsung for testing, btw). Also, what headphone you were using at the time? I tested with SE530, which is notorious for picking up hiss. But I am certain there are worst out there. Even so, wait till you hear the FSM-01 before you know what counts as really bad hissing - it is like having two mosquitos flying inside your ears.
My C421 are all current models btw.

I thought EMI was Electromagnetic interference, which comes from all electronic devices. It was my iPod Classic. Tested it as well with my iPod Video. Same thing happened. I was testing the latest components that start shipping this month from JDS Labs. Apparently they changed a few things inside. Anyways, I couldn't find the time to do the review so I sent it back, unfortunately.

EDIT: Please keep in mind I'm using some pretty sensitive CIEM's....

Yes, all electronic has some EMI, that's why I say 'of significant' as you can hardly find any typical strong EMI source in household than your cellphone (well, except for the microware). Maybe is because of your CIEM that you can pick up hiss and EMI more easily? Can't say for sure.

Quote:

Originally Posted by ShenaRingo326

.. given that i have certain IEM/headphones/earbuds and their specs, how should i choose an amp that has good synergy with it, using the specs/ratings that you've listed here?

As far as synergy is concerned, I tend to look for the opposite of each gear, meaning I am trying more to compensate gears rather than trying to compliment. For example, the great rendering of depth on C421-AD8620 pairs really well with IEM, which generally isn't good in this area. The more upfront C421-OPA2227 might go well with full size because they don't lack depth, but could use more richness.

However, synergy is really more of an issue for sub-$100 amps really, as many of the sub-$200 amps reviewed here have much less 'flavor' and sounds quite neutral overall. The difference are much less significant. Then again, less significant is probably still too significant in the ears of audiophiles.

Here is probably the proof in the pudding that ClieOS is the most thorough comparative amp reviewer on headfi. It's not just price and wishful thinking; it's observed, enjoyed, corroborated evidence. Well done.

Thanks for the comments, guys. As great and fun to play around portable amps, it is unlikely I'll continue with another amps shootout as this is getting kind of out of control for me. I think I almost double my yearly spending since I decided to do amp shootout at late last year. It has been fun but I'll stick back to IEM and earbuds for now.

I was really hoping you would do a sub-$500 shootout. Maybe you can get loaners from the companies or other members, I bet they'd be happy to loan them to you.

Quote:

Originally Posted by ClieOS

Thanks for the comments, guys. As great and fun to play around portable amps, it is unlikely I'll continue with another amps shootout as this is getting kind of out of control for me. I think I almost double my yearly spending since I decided to do amp shootout at late last year. It has been fun but I'll stick back to IEM and earbuds for now.

Thanks for the comments, guys. As great and fun to play around portable amps, it is unlikely I'll continue with another amps shootout as this is getting kind of out of control for me. I think I almost double my yearly spending since I decided to do amp shootout at late last year. It has been fun but I'll stick back to IEM and earbuds for now.

That seems a sensible and wise decision! Obviously, everyone would like to see more of these shootouts you do so well, but maybe you can try loaners as suggested above. Even so, you already done a nice job with the two shootouts you did. Personally, I'm happy as it is, as 200$ is my budget for a new portable amp...

Oh, I'll still review >$200 amps when I have the chance, but it just not going to be in a shootout fashion since that requires more than a handful of amps to make sense. Loaner is a valid idea, but I am half a world away from most amp makers and I don't want to bear the risk of having expensive amps shipping across the world and the responsibility of getting taxed or even worst, lost during shipping. It is just impractical in the long run.

Oh, I'll still review >$200 amps when I have the chance, but it just not going to be in a shootout fashion since that requires more than a handful of amps to make sense. Loaner is a valid idea, but I am half a world away from most amp makers and I don't want to bear the risk of having expensive amps shipping across the world and the responsibility of getting taxed or even worst, lost during shipping. It is just impractical in the long run.